Apparatus for treating exhaust gases of internal combustion engines



Jan. 3, 1933.l c. J. KRYZANOWSKY 1,893,372.

APPARATUS FOR TREATING EXHAUST GASES OF INTERNAL COMBUSTION ENGINES Original Filed Jan. ll. 1929 `5 Sheets-Sheet- 1 j Jan. 3, 1933.

c. .1. KR'YzANowsKf APPARATUS FOR TREATING EXHAUST GASES OF ITERNL COMBUSTION ENGINES original Filed'Jan. 11, 5 sheets-sheet 2 (air fly/'(21") I who,

INVENTOR Jan- 3, 1933-` c. J, KRY'zANoWsKY 1,893,372

APPARATUS FOR TREATING EXHAUST GASES OF INTERNAL COMBUSTION ENGINES original Filed Jn. 11. 1929 5 sheets-Sheet 3 WlTNV'ESSES i @M4/@wm Patented Jan. 3, 1933 UNITED STATES PATENT oFFlcEf CONSTANT J'. KRYZAN'OWSKY, OF BALTIMORE, MARYLAND, ASSIGN'OR TO MINE SAFETY.

ALPPLIANCFS COMPANY, 0F PITTSBURGH, vPENNSYLVANIA, A CORPORATION 0F PENNSYLVANIA, AND-H. J'. NEWMAR-K, OF YORK, N, Y. y

APPARATUS non 'ri-:EATING EXHAUST GASES or INTERNAL coMBUs'rIoN ENGINES Application led Jlanuary 11, 1929, Serial No. 331,868. Renewed May 13, 1932.

This invention relates to apparatus for purifying gas of combustion by elimination of objectionable constituents, and es ecially to apparatus for treating internal com ustion engine exhaust gas to catalytically convert the toxic and malodorous constituents of the gas into innocuous and odorless compounds.

Of the toxic gases, carbon monoxide is one ofthe most deadly, because of its insidious nature. This gas has neither odor, taste, nor

color, it produces no startling effects when breathed, and lethal amounts can usually be inhaled and combined withblood hemoglobin before the person exposed develops any other symptom than a feeling of drowsiness. Carbon monoxide is responsible for numerous fatalities, which most frequently are due to breathing of internal combustion engine ex-l haust gas, which commonly contain relatively large amounts of-this toxic substance. Such gas may, for example, leak into spaces occupied by industrial workers, or into closed automobiles.' Also, a common source is that of running automobile engines inclosed garages with insufficient ventilation. While some of these instances of poisoning are inadvertent,

`they are usually due to ignorance of vor carelessness with respect to the danger. Automo' bile and similar exhaust gas is also objectionable because of their disagreeable odor, vdue largely to. unburned fuel and oil together with decomposition products of those materials.

An object of the invention is to provide apparatus for catalytically purifying exhaust gas of combustion, which is simple and eiii- 'cient, which satisfactorily converts toxic constituentsinto innocuous substances, and 1n which the catalyst is indirectly heated by the heat contained the incoming exhaust gas.

'A further object is to provide apparatus of the type referred to which is lightin weight and compact, is provided with means actuated by gas flow for supplying air to the gas, is

provided with heat-exchanging means associated with the incoming gas and catalyst, is particularly adapted for use with internal combustion engines, and especially for installation in automotiveiehicle's, is automatic in of thesame apparatus taken on line III-III,

Fig. 1; Fig. 4 a side elevation of a-modiled form of apparatus; Fig. 5 a top plan View of the apparatus shown in Fig. 4; Fig. 6 a longitudinal section of. the apparatus shown in Fig. 4, taken on line VI-VI, Fig. 4; Fig. 7 a central-sectional View 'of another embodiment of the invention; and Fig. 8 a view partly in sectionl and partly in plan of the appa- -ratus shown in Fig. 7 the section `being taken on line VIII-VIII, Fig. 7.

The apparatus provided by thisinvention comprises a canister having a catalyst chamber provided with an inlet for incoming or raw gas, and an outlet for purified gas. An oxidizing catalyst is disposed' in the canister in the path of the gas, means are provided for admixing air with the raw gas, and means are also provided fortransferring heat from the incoming raw gas to the catalyst prior'to its contact with the catalyst.

Although various'means may be used for introducing air intofthe gas, it is preferred to i' l pass the raw gas through an,asp1rating nozzle which entrains air by jet action and which draws in air in proportion to the flow of'gas to the catalyst. The heating of the catalyst is accomplished by heat conducting means which absorbs heat from the incoming gas prior to its being mixed with air, and conducts it to the catalyst. Also, the apparatus is preferably provided with means for filtering the air drawn in through the nozzle, to prevent access of dust and 'dirt which might accumulate on the catalyst and impair its eliiciency.

Referring now to the drawings, Figs. 1 to 3 show the preferred embodiment, which com*- prises a canister 1 having an intake 2 for connection to the exhaust of an internal combustion engine 3, indicated generally in dotted lines in Fig. 1. This connection may be made directly to the exhaust port of the engine, in which case one device is used for each cylinder, or for each port where two cylinders -exhaust toa common port, or a single device that this end of the chamber is of decreasing cross sectional area. An oxidizing catalyst 6 is disposed in the chamber between end retaining screens 7.

' "Raw gas from intake 2 circulates in a passage 8 around the reduced portion of chamber 6, and passes into an aspirating nozzle 9 connected to the lower end of duct 5. This nozzle .is preferably of the multi-stage type which entraine air by jet action. A chamber 10 formed around the discharge orifice of the nozzle causes the gas to change direction and pass upwardly through screen 7 and the catalyst into an annular space 11 at the top of the canister, and thence through ducts 12 to a discharge outlet 13 connected toa pipe 13a leading to any desired point.

The air duct is preferably provided with means for filtering air supplied thereto, one form of which is shown connected to the upper end of the duct. It comprises a skeleton framework'of wire circles 14 of alternately large and small. diameter, suitably supported, and covered exteriorly with a layer of filter cloth 15 stretched over the wires. The interior of the filter thus formed is connected to the air duct, as shown in Fig. 1. An outer vaned casing 16 protects the cloth from mechanical damage.

When in use, the hot exhaust gas entering passage 8 circulates around the tapered portion of the chamber and gives up a portion of its heat to the walls 4a, thus heating the lcatalyst in that portion. The gas then enters nozzle9, entraining filtered air, and the raw gas-air mixture passes through the catalyst, where the carbon monoxide is converted to carbon dioxide, and other oxidizable constituents of the gases are catalytically and thermally acted upon. The puried gas enters chamber 11 and passes into ducts 12, leaving the apparatus from outlet 13.

The catalysts suitable for use in this apparatus begin to'be active, or are most ellicient, at somewhat 'elevated temperatures, and in order to drive off any condensed moisture and to bring them to operating temperature it is necessary to heat them when gas is first supplied after a period of inactivity. According to this invention, such heating is accomplished in the manner just explained, it being necessary usually to heat only a portion of the catalyst, because the reaction liberates enough.v heat to bring the balance of the catalyst up to operating temperature.

This conduction of heat to the catalyst, to indirectly heat it by the incoming gas, is necessary in most instances because when mixed with air the gas is cooled to a point where it is then incapable of heating the catalyst SuliCiently. The heating may be, and preferably is, increased by heatconducting tins 18 arranged in conduit'S and connected to walls 4a.. It may be further increased bylining the outer wall of chamber Stwvith a heat insulating material 19, which reduces conduction of heat outwardly from the chamber.

In'the modification shown in Figs. 4 to 6, the catalyst is disposed in a canister 2O having an inlet 21 for raw gas and an outlet 22 for purified gas, screens being used as before when necessary. The raw gas enters through an intake 24 in a fitting 25, and circulates in a passage 26 around an aspirating nozzle 27 similar to that previously described, carried in fitting 25. The intake is connected to the exhaust of an engine not shown, and the gas passes from the nozzle into inlet 21- of 'the canister.

A series of parallel metallic 'plates 28 emi" bedded in the catalyst adjacent inlet 21 are mounted in spaced relation upon a plurality of tubular members 28a which are connected at their lower ends to the fitting' which forms the discharge end of nozzle 27, as shown in Fig. 6. These members receivemetallic or -other heatconducting rod's 29 connected at their lower ends to a plurality of fins 30 arranged in conduit 26. The rods make a sliding fit with the' tubes, and heat absorbedl by the fins from hot gas entering the conduit is cond-noted by the rods to the plates in the catalyst. This heats the catalystv to operating temperature, as in the receding modification. A

The canister and tting are clamped together by a U-shapedv spring. rod 31 pivotally mounted in studs 32 formed on the fitting, which rod yieldingly engages grooved proj ections 33 formed on the canister to hold these members in gas-tight relation, but permits ready removal of the canister Ashould it be necessary to renew the Icatalyst.

externally through a sleeve 44 to an exhaust 45 of an internal combustion engine. The nozzle extends through spaced partition walls '46 and 47 and discharges into a space 48 formed by a longitudinally disposed cylindrical screen 49`which extends from partition 47 to top 4l. A bed 5 0 of an oxidizing catalyst is supported between screen 49 and another screen 51 spaced from shell 40.

The entraining orifices of nozzle 43 lie in a space formed between partition 46 and lbottom 42, and air is supplied tothe nozzles through a bed 52 of a iltering medium supported laterally between screens 53 and al, the latter being spaced from.the .shell to form an air passage 55 into which air passes from peripherally disposed inlets 56 formed in bottom 42. Y

The heating means shown in this modification comprises a tubular ring' 57 disposed within sleeve 44, and provided with radially disposed heat absorbing tins 58. Extending upwardly from the ring through the air filter and into the catalyst are a plurality of tubes 59, closed at their extended ends and provided with parallel fins 6() embedded in the catalyst. These tubes are arranged to lie adjacent to screen 49, and where they pass through the ilter they are insulated by a lagging 61. A heat exchanging substance is placed inside of ring 57 to absorb heat taken up from the gas by fins 58, and to conductthe heat through tubes 59 and fins 60 to the catalyst. For this purpose a material vaporizable at the temperature attained in. the ring is most suitable. For example, a small amount of mercury or diphenyl oxide placed in the ring will. be vaporized by theheat of the incoming gas, the vapor will pass into the tubes, and the heat in'the vapor will be take'n up by the fins and liberated to the catalyst, causing the vapor to condense and fall back into the ring as a li uid where against vaporized.

he apparatus is also provided withmeans for preventing damage should backfir occur.

The means shown comprises a ball 61 vheld by spring 62 in a conical aperture 63, Fig. 7, formed in top 41, the outer end of the spring bearing against a yoke 64 connectedto such top. The ball valve prevents passage of gas during normal uoperatiom but should an explosion take plae, it is forced outwardly, venting the explosion pressure to the atmosphere. This or other safety devices may be incorporated, in the preceding embodiments.

-In the use of this apparatus, raw hot gas passes into the nozzle from exhaust pipe 45, 4

heating the catalyst inthe manner described,

A multi-stage aspirating and entraining air drawnthroughthe filter bed. The gas-air mixture is dischargedinto chamber 48 and passes through the catalyst where the gas is converted into non-toxic, practically 'inodorous substances, and the puriiied gas passes into an annular passage -65 formed between screen '5,1 and'shell 40,1` and thence to the atmosphere through open-v ings 66 formed in top 41.

When used withstationary engines, this form of apparatus is usually in an upright position. AIn time the .lter medium' and catalyst may tend to pack down, and in order to prevent the air and gas from passing through the free spaces formed by such compacting, and thus being ineiiiciently treated,

annular baiiies 67 and 68 are arrangedv in the catalyst and air chambers, respectively, these only the canister is removed in such a contingency, the connection between the fitting and motor not being disturbed.

This invention is not directed toward the use o f any particular catalyst. A number of oxidizing catalysts for use in converting car-- bon monoxide to dioxide, or for'oxidizing hydrocarbon gases are well known. Because of the high content of water vapor in internal combustion engine exhaust gas the catalyst must be maintained during use above the boiling point of water, to prevent condensation of moisture on it. Also, the large amount of 'oxidizable hydrocarbonsf and carbon monoxide in'such gas makes necessary the use of a highly activecatalyst, which is capable of eiiciently operating at the high temperatures kgenerated by the reactions. These restrictions are such that the known catalysts referred to may not .all be suitablev for this ap-A plication. However, although the catalyst `forms no part of this invention, nickel or cobalt oxides, manganese dioxide, or ferrie oxide, when in `-catalytically i active condition are suitable for use under these conditions. In order to present as large a gas-catalyst contact ,surface as possible, it is preferred to support the catalyst on a suitable carrier disposed in the catalyst chambers in the path of the gas. It is desirable to retard the flow of the gas through the catalyst f in order to prolong its contact therewith, but -the manneroie disposing this material should be such that the increase in resistance to gas How does not interfere with efficient operati on of the engine. j l y In Athe operation of4 the apparatus with a suit-able catalyst, -it is necessary to so oper- -complexer delicate mechanism.

ate as to prevent condensation of water on the catalyst. This is accomplished in part by connecting the apparatus-as close to the engine as practicable, and by operating with .the catalyst at a temperature such that con- Of course,l

densation will not take place. some water vapor condenses from the residual gas left in the chambers-when the engine is shut off, and for this reason the catalyst should be heated'to drive oil the condensed moisture and to bring it up` to operating temperature when the engine is started. These and other factors are provided for by the automatic control described.

The apparatus provided by the invention is compact, light in weight, and may be installed Without changing- 'present engine dcsign. It is fully'autoniatic in operation, and this feature is secured without the use of The apparatus is simple in construction, and, considering its purpose, inexpensive. lt effectively destroys the carbon monoxide toxicity of exhaust gas, and also renders such gas odorless, or practically so.

Other means of heating the catalyst, and other modifications of construction are shown in tivo copending applications, Serial Numbers 331,866 and 331,867, filed by me of even date herewith. I

According to the provisions of the patent statutes, I have explained the principle and operation of my invention, and have illustrated and described What I-now consider' o represent its best embodiment. However. I desire to haveitunderstood that, Within the scope of the appended claims, the invention may be practiced otherwise than as specitically illusfrated and described.

I claim:

1. Apparatus for catalytically purifying exhaust gas, comprising a canister provided with an inlet for raw gas and an outlet for purified gas, an oxidiz'ng catalyst disposed in said canister in the path of said raw gas, and means for indirectly heating the catalyst from the raw gas prior to contact therewith.

2. Apparatus for catalytically purifying exhaust gas, comprising a' canister provided with an inlet for raw gas and an outlet for purified gas, an oxidizing catalyst disposed in said canister in the path of said raw gas, and heat conducting means in said inlet associated With-the catalyst for indirectly heating the catalyst from the raw gas prior to its contact with the catalyst.

3. Apparatus for catalytically purifying exhaust gas, comprising a canister provided with an inlet for raw gas and 'an outletfor purified gas, an oxidiz'ng catalyst disposed in said canister in the path of said raw gas, and metallic heat conducting members `disposed in said inlet and extending to a portion of the catalyst for indirectly heating the catalyst by conduction from the raw gas.

with an inlet for raw gas and an outlet for purified gas, an oxidizing catalyst disposed in said canister' in the path of said ran1 gas, means for indirectly heating the catalyst from the raw gas prior to its contact with the catalyst, 'and means for adlnixing air in a continuous stream with said gas prior to contact with the catalyst'.

5. Apparatus for catalytically purifying exhaust gas, comprising a canisterprovided With an inlet for raw gas and an outlet for purified gas, an oxidizing catalyst disposed in said canister in the path of saidraw gas, heat conducting means in said inlet for transferring heat from said raw gas to the catalyst prior to its Contact with the catalyst, and means associated with the inlet for-admixing air with said gases subsequent to contact with said heat conducting means but prior to contact with the catalyst.

6. Apparatus for catalytically purifying internal combustion engine exhaust gas, comv prising a canister provided with an inlet for -raw gas and an outlet for purified gas, an

' multi-stage aspirating nozzle in said inlet for entraining air by flow of the raw gas, means disposed in said inlet for transferring heat byr conduction from said gas t0 the catalyst prior to its contact therewith, and means for filtering air associated withv said nozzle.

8. Apparatus for catalytically purifying internal combustion engine exhaust gas, comprising a sheet metal canister having a. longitudinally disposed air duct and an annular elongate catalyst chamber surrounding said duct and tapering toward it at one end, an oxidizing catalyst disposed in said chamber,

an inlet for raw gases surrounding said tapered portion, a plurality of heat-conducting tins in said inlet and connected to said tapered portion for heating said catalyst by conduction from said gas, and a multi-stage aspirating nozzle disposed in said inlet for entraining air upon passage of raw gas through the nozzle. Y

In testimony whereof, I sign my name.'

CONSTANT J. KRYZANOWSKY.

4. Apparatus for catalytically purifying exhaust gas, comprising a. canister provided 

